feat(dpr): able to update dpr by resize

[Justin-ZS]

Summary

• Allow dynamic devicePixelRatio updates through the resize() method
• Add Layer.updateDpr() to keep canvas context dpr in sync

Fix

apache/echarts#21386

Usage

zr.resize({
    width: 800,
    height: 600,
    devicePixelRatio: window.devicePixelRatio
});

Changes

• Add optional devicePixelRatio parameter to PainterBase.resize() interface
• Add Layer.updateDpr() method
• Update Painter.resize() to trigger layer resize on dpr change
• Expose devicePixelRatio option in ZRender.resize()

[plainheart]

I tend to completely replace the constant devicePixelRatio in favor of the new getDevicePixelRatio() function.

[Justin-ZS]

done

[plainheart]

The same here.

[plainheart]

Or just let the DPR fall back to 1 and only do it in zrender constructor?
https://github.com/Justin-ZS/zrender/blob/5a52347e793a2eeffcc9eaed5dd4538087755eac/src/zrender.ts#L92

[Justin-ZS]

I prefer to do it only in the Canvas Painter constructor.

[Justin-ZS]

@plainheart
Since this.dpr has already been initialized before, I removed this line.
Please let me know if forcing 1 here was intentional.